Crabgrass is the bane of many homeowners and if left alone can quickly take over a lawn, garden bed, or even concrete surfaces. With so many different species of crabgrass on the planet, it can be difficult telling them apart. From short to southern varieties, here are the different types of crabgrass commonly found in the world.
Crabgrass is officially part of the family of Digitaria, which is a Latin term meaning "finger." There are over 33 varieties of crabgrass within this genus and not all of them are considered weeds—some types of crabgrass can be eaten by humans and animals alike. Certain types of crabgrass are native to North America, but many were brought over from Europe, Asia, and Africa.
Long crabgrass is also referred to as hairy crabgrass. This variety comes from Asia, Europe, and Africa, but is also found in North America. Hairy crabgrass can actually be cultivated as food but will invade your lawn with ease and can grow up to two feet in height. Fortunately, long crabgrass does not stand up well to repeated mowing sessions and will go away with a little effort. You can also apply mulch to the area if you want to prevent hairy crabgrass from growing in the first place.
Smooth crabgrass, also referred to as small crabgrass, is the most common variety found in lawns across North America. This type of weed comes from Asia and Europe and features a smooth, hairless leaf. Smooth crabgrass grows close to the ground and often avoids mower blades. If left unchecked, this crabgrass can reach heights of over six inches. You can eradicate smooth crabgrass by using a preemergent herbicide, which will stop growth before it takes hold in the soil.
Native to Australia and Asia, Asian crabgrass is unique from its smooth and long counterparts. This crabgrass, which is growing in popularity in North America, features a seed head that starts off the main flower stem. The branches of this variety are about a quarter to an eighth inch apart and can be both smooth and hairy.
Southern crabgrass (digitaria cilaris) is actually native to several different continents including the Americas, Asia, and Africa. Some countries use this crabgrass variety as a means of erosion control and foraging. Others consider it a weed. Southern crabgrass is characterized by its large and hairy leaves, making it difficult to tell apart from hairy crabgrass.
Other Forms of Crabgrass
There are many other kinds of crabgrass that may or may not be in your area. This includes blanket crabgrass, which features short and hairy leaves; Indian crabgrass, which has leaves smaller than one inch; and Texas crabgrass, which flourishes in hot weather and dry or rocky soil. Other types of crabgrass exist and are often named according to their location. Examples of this include Carolina and Madagascar crabgrass. Others are named after their appearance, such as cotton panic, comb finger, and naked crabgrass. Consult your local area to find out which kinds you might have in your lawn.
Even with a proper description, it can be difficult identifying what type of crabgrass is in your lawn. To help with the identification process, refer to photos of the crabgrass that are prevalent in your area. You should be able to narrow down the type by examining the leaf characteristics and size (though Southern and long crabgrass are closely related). Once you properly identify the crabgrass you can begin the process of removing it from your lawn.
There are many ways you can discourage the growth of crabgrass in your lawn. You can start by cutting your grass at the lowest setting and discard the clippings. If the lawn is infested with crabgrass, then you will need to rake out all the vegetation and dispense new grass seed. Remove any crabgrass in the future by hand and consider applying a preemergent crabgrass herbicide next spring.